1. Field of the Invention
The present invention relates generally to a slider having a magnetic head and a magnetic disk apparatus with the slider, and more particularly to a slider floating up over a surface of a magnetic recording medium in an actuating time of a magnetic disk apparatus and a magnetic disk apparatus with the slider.
2. Description of the Prior Art
A magnetic disk operated according to a contact start-stop (CSS) method in which a floating type head is used has been widely adopted. In the CSS method, a slider having a magnetic head is put on a CSS region of a magnetic disk surface in a halt time of the magnetic disk apparatus, and the slider is floated up over a surface of a magnetic disk in an actuating time of the magnetic disk apparatus. In general, a reading and writing magnetic head is attached to the slider, the slider is supported by a suspension, and the slider is moved over the magnetic disk with the movement of the suspension.
The reason that the slider having the magnetic head floats up over the magnetic disk surface in the actuating time is that an air flow occurs on the magnetic disk surface when the magnetic disk is rotated. That is, the magnetic head slider floats up according to a principle of a dynamic air bearing.
In the above magnetic disk apparatus, the apparatus has been gradually downsized, and information can be recorded in the magnetic disk at a high density. Therefore, a flying height of the slider is gradually lowered. However, in cases where a flying height of the slider is lowered, there is a drawback that the slider contacts with asperities of the magnetic disk surface and is damaged. To prevent the drawback, the roughness of the magnetic disk surface is lowered to prevent the contact of the slider with the magnetic disk.
However, because a contact area between the slider and the magnetic disk in the CSS region is enlarged as the surface roughness of the magnetic disk is lowered, the slider easily adheres to the magnetic disk. In this case, there is another drawback that a motor torque required to rotate the magnetic disk is increased and the suspension supporting the magnetic head is easily damaged when the rotation of the magnetic disk is started.
To reduce the adhesion of the slider to the magnetic disk, a plurality of pads (hereinafter, also called projecting portions) are provided on an air bearing plane (hereinafter, also called a floating plane or a rail plane) of the slider facing the magnetic disk, so that the contacting area between the slider and the magnetic disk is reduced. This technique is, for example, disclosed in a Published Unexamined Japanese Patent Application No. S63-37874 (1988).
However, in cases where the pads are provided on the rail plane, the load of HGA (head-gimbal assembly) is put on the pads, so that there is another drawback that the pads are easily worn out because of the friction between the pads and the magnetic disk. Also, there is another drawback that the pads prevent the magnetic head be set to be close to the magnetic disk surface.